Another Turbo Question

[projectgsr]

I was trying to look at other threads to see if my question could be answered but I had trouble finding a good answer. I want to know what all I should do if I want to boost an H22a4 (98 Type SH Prelude). The engine has like 120,000 miles. So should I just get it rebuilt with lower compression piston's? Also I've heard that the walls are very thin on this engine so should I get the block sleaved? One more question. If I do put like a Greddy kit on without building the engine, about how much psi and how much hp can I expect?

[Polygon]

I am not big on Honda engines so I don't really know how much power you will get, but you can expect between 6-10 HP per PSI.

As for the engine, the first thing I would do is have a compression test done to make sure that the engine can even be turbo-charged reliably. When it comes to compression ratio I don't suggest going over 9:1 on a street driven car that will see pump gas. I would keep it between 8:1 and 9:1. If you're currently higher than that then I would get lower compression pistons. With the higher compression the engine will be more responsive out of boost but no amount of tuning will save you from some bad fuel. Besides the advantages of running lower compression overshadow the benefit of running higher compression. Either way I would sleeve the block but you don't have to depending on how much boost you plan to run. I wouldn't run over 6-7 PSI non-intercooled and no more than 10 intercooled without sleeving it.

[projectgsr]

Thanks for the info. Even though your not big on Honda engine's you seem to know alot about turbo charging. Now I just need some Honda expert to let me know about the H22.

[94PreludeJDM]

The topic has been covered in the prelude forum, so I suggest looking there for some more info, but I'll give you a brief overview of what the general consensus is in that forum. Like Polygon said, you can expect a 6-10hp gain per PSI. Test your compression and everything, make sure your engine is still solid. The most you should run on stock internals with an H22 is 7PSI, but apparently 6PSI is best for a daily driver. If you plan doing anything over 7PSI, you're gonna have to beef up your internals, lower your compression, etc. Some people say that the walls really aren't that thin and that sleeving the block isn't a necessity, but it's good to be safe. If you end up getting new pistons, you should probably sleeve the block anyway though. With the Greddy kit, You could probably expect a 50-60hp gain. If you do boost, make sure to get it dyno tuned, and make sure you have a good fuel management system.